Western Massachusetts enjoys improved summer air quality

The Republican | Dave RobackTrey Scott, of Springfield, glides down the new skatboard ramp at Lincoln Grove Park in Chicopee in June. The Pioneer Valley is enjoying a summer with some of the cleanest air of the last decade.

The Pioneer Valley is enjoying a summer with some of the cleanest air of the last decade.

New power plants and cars that emit fewer pollutants are among the reasons why the air has been relatively smog-free, but the struggling economy may also be a factor, according to Paul J. Miller, the deputy director of the Northeast States for Coordinated Air Use Management.

His agency was created by the states in the Northeast to address air-quality issues.

“The economy could have an overall effect in suppressing the amount of electricity used” and power-plant emissions are a prime contributor to ground-level ozone, or smog, Miller said.

Nationally, electricity generation increased every year from 2001 to 2007, when it peaked, according to the U.S. Department of Energy. No year following that has matched 2007 for power generation.

At the same time, the amount of coal that power plants are using has declined, as more switch to natural gas, and coal is the fuel that produces the most polluting emissions, Miller said.

“Based on the summer so far, I would rate 2011 in Western Massachusetts as among the cleanest in the past decade. The summer isn’t over yet, though, so there’s still the chance of high ozone days through September, and maybe even early October,” he said.

Air quality has been improving steadily for three decades due to more stringent federal and state pollution standards.

In 1983, there were 84 days when one or more air quality sensors in the state registered a violation of the ozone standard. In 2009, there were only seven – although the mild weather that summer was the primary reason.

Since 2002, there have been 24 days a year, on average, on which any of the 14 sensors in the state recorded a violation.

In 2011, to date, there have been 10 days when violations occurred. In Western Massachusetts, there are sensors in Chicopee, Amherst, Ware and Adams.

This year, only the sensor in Chicopee has registered a violation, and it has recorded two – on July 11 and 21.

“I think the past three summers, regardless of the economic situation, have shown that the clean air measures Massachusetts and other states have been putting into place have been working,” Miller said.

Weather plays a major role in the region’s air quality. On hot days in summer, more smog is formed.

For instance, in 2009, when the region experienced the fewest bad air days on record, there were no days in June and July when the temperature in Westfield went above 87 degrees.

“Year to year, weather variability can mask a lot of things,” he said.

In addition to using less electricity due to the recession, people are also driving less, which means fewer tailpipe emissions, which contribute to smog.

According to the U.S. Department of Transportation, total miles driven by vehicles in the nation rose every year from 1986 through 2007. In 2008, the figure fell 2 percent compared to 2007. Mileage in 2007 remains the most for any year.